准备工作：
1. 首先，打开vs.net，新建一个C#类库项目。如叫 IpBoxControl。
2. 在vs.net 的菜单，“项目”，“添加用户控件”，把这个用户控件取名为IpBox。
3. 把一个Panel从工具箱拖到IpBox的设计视图，取名为panel1，设置panel1的Location为(0,0)，Size为(136, 20)，BorderStyle为Fixed3D，BackColor为Window。
4. 把一个TextBox从工具箱拖到panel1里。取名为textBox1，设置textBox1的Location为(8,0)，Size为(20, 14)，BorderStyle为None，MaxLength为3，TextAlign为Center，Text为““，BackColor为Window。
5. 把一个Label从工具箱拖到panel1里。取名为label1，设置label1的Location为(32, 0)，Size为(8, 14)，BorderStyle为None，TextAlign为TopCenter，Text为“.”，BackColor为Window。
6. 选取textBox1和label1，textBox1复制、粘贴上3份，label1复制、粘贴上2份。分别命名为textBox2、label2，textBox3、label3，textBox4。Location分别为(40, 0)、(64, 0)、(72, 0)、(96, 0)、(104, 0)。
7. 设置IpBox的Location为(0,0)，Size为(136, 20)。
现在一个ip box 的形状已经出来了，接下来要在程序里实现输入的控制。
源代码如下：
using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Windows.Forms;
using System.Text.RegularExpressions;
namespace XRascal.Controls
{
///
1<summary>
2/// UserControl1 的摘要说明。
3/// </summary>
[
Description("横刀夺爱的 Ip Box 控件！用于输入 IP 地址。"),
ToolboxBitmap(typeof(XRascal.Controls.IpBox))
]
public class IpBox : System.Windows.Forms.UserControl
{
private System.Windows.Forms.Panel panel1;
private System.Windows.Forms.TextBox textBox4;
private System.Windows.Forms.Label label3;
private System.Windows.Forms.TextBox textBox3;
private System.Windows.Forms.Label label2;
private System.Windows.Forms.TextBox textBox2;
private System.Windows.Forms.Label label1;
private System.Windows.Forms.TextBox textBox1;
private string _text = "";
///
1<summary>
2/// 必需的设计器变量。
3/// </summary>
private System.ComponentModel.Container components = null ;
public IpBox()
{
// 该调用是 Windows.Forms 窗体设计器所必需的。
InitializeComponent();
// TODO: 在 InitializeComponent 调用后添加任何初始化
}
///
1<summary>
2/// 清理所有正在使用的资源。
3/// </summary>
protected override void Dispose( bool disposing )
{
if ( disposing )
{
if (components != null )
{
components.Dispose();
}
}
base .Dispose( disposing );
}
#region 组件设计器生成的代码
///
1<summary>
2/// 设计器支持所需的方法 - 不要使用代码编辑器
3/// 修改此方法的内容。
4/// </summary>
private void InitializeComponent()
{
this .panel1 = new System.Windows.Forms.Panel();
this .textBox4 = new System.Windows.Forms.TextBox();
this .label3 = new System.Windows.Forms.Label();
this .textBox3 = new System.Windows.Forms.TextBox();
this .label2 = new System.Windows.Forms.Label();
this .textBox2 = new System.Windows.Forms.TextBox();
this .label1 = new System.Windows.Forms.Label();
this .textBox1 = new System.Windows.Forms.TextBox();
this .panel1.SuspendLayout();
this .SuspendLayout();
//
// panel1
//
this .panel1.BackColor = System.Drawing.Color.White;
this .panel1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
this .panel1.Controls.Add( this .textBox4);
this .panel1.Controls.Add( this .label3);
this .panel1.Controls.Add( this .textBox3);
this .panel1.Controls.Add( this .label2);
this .panel1.Controls.Add( this .textBox2);
this .panel1.Controls.Add( this .label1);
this .panel1.Controls.Add( this .textBox1);
this .panel1.Location = new System.Drawing.Point(0, 0);
this .panel1.Name = "panel1";
this .panel1.Size = new System.Drawing.Size(136, 20);
this .panel1.TabIndex = 1;
//
// textBox4
//
this .textBox4.BorderStyle = System.Windows.Forms.BorderStyle.None;
this .textBox4.Location = new System.Drawing.Point(104, 0);
this .textBox4.MaxLength = 3;
this .textBox4.Name = "textBox4";
this .textBox4.Size = new System.Drawing.Size(20, 14);
this .textBox4.TabIndex = 6;
this .textBox4.TextAlign = System.Windows.Forms.HorizontalAlignment.Center;
this .textBox4.KeyPress += new System.Windows.Forms.KeyPressEventHandler( this .textBox4_KeyPress);
//
// label3
//
this .label3.Location = new System.Drawing.Point(96, 0);
this .label3.Name = "label3";
this .label3.Size = new System.Drawing.Size(8, 14);
this .label3.TabIndex = 5;
this .label3.Text = ".";
this .label3.TextAlign = System.Drawing.ContentAlignment.TopCenter;
//
// textBox3
//
this .textBox3.BorderStyle = System.Windows.Forms.BorderStyle.None;
this .textBox3.Location = new System.Drawing.Point(72, 0);
this .textBox3.MaxLength = 3;
this .textBox3.Name = "textBox3";
this .textBox3.Size = new System.Drawing.Size(20, 14);
this .textBox3.TabIndex = 4;
this .textBox3.TextAlign = System.Windows.Forms.HorizontalAlignment.Center;
this .textBox3.KeyPress += new System.Windows.Forms.KeyPressEventHandler( this .textBox3_KeyPress);
//
// label2
//
this .label2.Location = new System.Drawing.Point(64, 0);
this .label2.Name = "label2";
this .label2.Size = new System.Drawing.Size(8, 14);
this .label2.TabIndex = 3;
this .label2.Text = ".";
this .label2.TextAlign = System.Drawing.ContentAlignment.TopCenter;
//
// textBox2
//
this .textBox2.BorderStyle = System.Windows.Forms.BorderStyle.None;
this .textBox2.Location = new System.Drawing.Point(40, 0);
this .textBox2.MaxLength = 3;
this .textBox2.Name = "textBox2";
this .textBox2.Size = new System.Drawing.Size(20, 14);
this .textBox2.TabIndex = 2;
this .textBox2.TextAlign = System.Windows.Forms.HorizontalAlignment.Center;
this .textBox2.KeyPress += new System.Windows.Forms.KeyPressEventHandler( this .textBox2_KeyPress);
//
// label1
//
this .label1.Location = new System.Drawing.Point(32, 0);
this .label1.Name = "label1";
this .label1.Size = new System.Drawing.Size(8, 14);
this .label1.TabIndex = 1;
this .label1.Text = ".";
this .label1.TextAlign = System.Drawing.ContentAlignment.TopCenter;
//
// textBox1
//
this .textBox1.BorderStyle = System.Windows.Forms.BorderStyle.None;
this .textBox1.Location = new System.Drawing.Point(8, 0);
this .textBox1.MaxLength = 3;
this .textBox1.Name = "textBox1";
this .textBox1.Size = new System.Drawing.Size(20, 14);
this .textBox1.TabIndex = 0;
this .textBox1.TextAlign = System.Windows.Forms.HorizontalAlignment.Center;
this .textBox1.KeyPress += new System.Windows.Forms.KeyPressEventHandler( this .textBox1_KeyPress);
//
// IpBox
//
this .Controls.Add( this .panel1);
this .Name = "IpBox";
this .Size = new System.Drawing.Size(136, 20);
this .panel1.ResumeLayout( false );
this .ResumeLayout( false );
}
#endregion
private void textBox1_KeyDown( object sender, System.Windows.Forms.KeyEventArgs e)
{
//System.Text.Encoding.GetEncoding(0).GetString();
}
private void textBox1_KeyPress( object sender, System.Windows.Forms.KeyPressEventArgs e)
{
MaskIpAddr( textBox1, e );
}
private void textBox2_KeyPress( object sender, System.Windows.Forms.KeyPressEventArgs e)
{
MaskIpAddr( textBox2, e );
}
private void textBox3_KeyPress( object sender, System.Windows.Forms.KeyPressEventArgs e)
{
MaskIpAddr( textBox3, e );
}
private void textBox4_KeyPress( object sender, System.Windows.Forms.KeyPressEventArgs e)
{
MaskIpAddr( textBox4, e );
}
private void MaskIpAddr( System.Windows.Forms.TextBox textBox, KeyPressEventArgs e)
{
int len = textBox.Text.Length;
if (Char.IsDigit(e.KeyChar) || e.KeyChar == '.' || e.KeyChar == 8)
{
if (e.KeyChar != 8)
{
if (len == 2 && e.KeyChar != '.')
{
string tmp = textBox.Text + e.KeyChar;
if ( textBox.Name == "textBox1" )
{
if (Int32.Parse(tmp)> 223) // 进行验证
{
MessageBox.Show( tmp + " 不是一个有效项目。请指定一个介于 1 和 223 之间的数值。");
textBox.Text = "223";
textBox.Focus();
return ;
}
textBox2.Focus();
textBox2.SelectAll();
}
else if ( textBox.Name == "textBox2" )
{
if (Int32.Parse(tmp)> 255)
{
MessageBox.Show( tmp + " 不是一个有效项目。请指定一个介于 1 和 255 之间的数值。");
textBox.Text = "255";
textBox.Focus();
return ;
}
textBox3.Focus();
textBox3.SelectAll();
}
else if ( textBox.Name == "textBox3" )
{
if (Int32.Parse(tmp)> 255)
{
MessageBox.Show( tmp + " 不是一个有效项目。请指定一个介于 1 和 255 之间的数值。");
textBox.Text = "255";
textBox.Focus();
return ;
}
textBox4.Focus();
textBox4.SelectAll();
}
else if ( textBox.Name == "textBox4" )
{
if (Int32.Parse(tmp)> 255)
{
MessageBox.Show( tmp + " 不是一个有效项目。请指定一个介于 1 和 255 之间的数值。");
textBox.Text = "255";
textBox.Focus();
return ;
}
}
}
if (e.KeyChar == '.')
{
if ( textBox.Name == "textBox1" && textBox.Text != "" )
{
textBox2.Focus();
textBox2.SelectAll();
}
if ( textBox.Name == "textBox2" && textBox.Text != "" )
{
textBox3.Focus();
textBox3.SelectAll();
}
if ( textBox.Name == "textBox3" && textBox.Text != "" )
{
textBox4.Focus();
textBox4.SelectAll();
}
if ( textBox.Name == "textBox4" && textBox.Text != "" )
{
}
e.Handled = true ;
}
}
else
{
if ( textBox.Name == "textBox1" && textBox.Text == "")
{
}
if ( textBox.Name == "textBox2" && textBox.Text == "")
{
textBox1.Focus();
textBox1.SelectionStart = textBox1.Text.Length;
}
if ( textBox.Name == "textBox3" && textBox.Text == "")
{
textBox2.Focus();
textBox2.SelectionStart = textBox2.Text.Length;
}
if ( textBox.Name == "textBox4" && textBox.Text == "")
{
textBox3.Focus();
textBox3.SelectionStart = textBox3.Text.Length;
}
e.Handled = false ;
}
}
else
e.Handled = true ;
}
[Browsable( true )]
///
1<summary>
2/// 获取 IpBox 的文本。
3/// </summary>
public new string Text
{
get
{
if ( textBox1.Text == ""
|| textBox2.Text == ""
|| textBox3.Text == ""
|| textBox4.Text == "")
{
_text = "";
return _text;
}
else
{
_text = Convert.ToInt32(textBox1.Text).ToString() + "." + Convert.ToInt32(textBox2.Text).ToString() + "." + Convert.ToInt32(textBox3.Text).ToString() + "." + Convert.ToInt32(textBox4.Text).ToString();
return _text;
}
}
/* set //
{
if(value != null)
{
// 255-255-255-255
//string pattern = @"^([1-9]|\d{2}|1[0-9]{1,2}|2[0-5]{2})\.(\d{1,2}|1[0-9]{1,2}|[1-2][0-5]{2})\.(\d{1,2}|1[0-9]{1,2}|[1-2][0-5]{2})\.(\d{1,2}|1[0-9]{1,2}|[1-2][0-5]{2})$";
// 223-255-255-255
string pattern = @"^([1-9]|\d{2}|1[0-9]{1,2}|2[1-2][1-3])\.(\d{1,2}|1[0-9]{1,2}|[1-2][0-5]{2})\.(\d{1,2}|1[0-9]{1,2}|[1-2][0-5]{2})\.(\d{1,2}|1[0-9]{1,2}|[1-2][0-5]{2})$";
if( !Regex.IsMatch(value , pattern) )
{
_text = "";
throw new Exception("IP 地址格式错误！");
}
else
{
string[] ipnum = value.Split('.');
textBox1.Text = ipnum[0];
textBox2.Text = ipnum[1];
textBox3.Text = ipnum[2];
textBox4.Text = ipnum[3];
}
}
_text = value;
}
*/
}
}
}
最后，我们要来测试这个控件：
在项目的解决方案里，右击解决方案的属性，新建一个C# 的Windows应用程序项目，取名为TestIpBox。
双击打开 Form1.cs的设计视图，右击工具箱，“添加/移除项”，“浏览”找到刚做好的 dll ，选择，确定。把这个控件从工具箱里拖到Form1的设计视图里。
把 TestIpBox 设成启动项目，按 F5 测试。